Arendelle's Ice Queen Elsa is in the house! Idina Menzel took the stage inside L.A.'s Dolby Theatre on Sunday, March 2 to belt out "Let It Go," the smash, viral phenom song from Frozen. The instantly-beloved animated Disney film has dominated box offices worldwide since its November 2013 (over $1 billion grossed globally so far!) — and the musical fairy tale's accompanying soundtrack album has spent five weeks at number one on the Billboard 200.

Written by Kristen Anderson-Lopez and Robert Lopez, "Let It Go," the anthem of Menzel's character Queen Elsa, has been a highlight of "Sing-A-Long" screenings of the flick. It's nominated in the Best Original Song category alongside "Happy" from Despicable Me 2, "Ordinary Love" from Mandela: Long Walk to Freedom and "The Moon Song" from Her.

Tony-winning actress Menzel, 42, recently revealed that her four-year-old son Walker Diggs (whom she shares with ex Taye Diggs) is among the millions of young fans who can't stop singing "Let It Go" himself. "My son sings let it go back to me in the bathtub!" she said last month on Good Morning America.

Of the Frozen and "Let It Go" phenom, she added: "It's about owning your own power, owning who you are, what makes you compelling, fierce hong girls and not caring what people think. This is a dream come true. I am just having fun with it."

Watch the clip — and Menzel's crazy high-note at the end, which she may or may not have hit — now!